Code 811 means the IRS is reviewing your return for math errors or missing information
When you see code 811 on your IRS notice, it means the IRS found something that doesn't match—a math error, a missing form, income reported twice, or a number that doesn't line up with what your employer or bank reported to them. The IRS is holding your refund while they verify the details. This is not a rejection. It is a pause.
The timeline depends on what triggered the code. If it is a straightforward math error the IRS caught, you may see your refund within two to four weeks after the notice date. If the IRS needs you to send documents or correct information, the clock restarts when they receive what you send—and that can take another four to eight weeks. If you do nothing, your refund stays frozen indefinitely.
The IRS does not contact you by phone or email about code 811. You will receive a paper notice in the mail. That notice will tell you exactly what they found and what action, if any, you need to take.
Key Takeaways
- Code 811 means the IRS found a discrepancy on your return and is reviewing it before releasing your refund.
- straightforward errors the IRS can fix on their own typically result in refunds within two to four weeks of the notice date.
- If you need to send documents or file an amended return, the review clock restarts when the IRS receives your response.
- The IRS will send you a paper notice explaining what they found and whether you need to respond.
- Calling the IRS about code 811 will not speed up the process, but you can check the status of your return using the IRS Where's My Refund tool.
What the IRS actually found on your return
Code 811 covers several different situations. The most common are a math error (you wrote $5,000 but the form shows $50,000), a missing schedule or form (you claimed a deduction but did not attach the required documentation), or a mismatch between what you reported and what was reported to the IRS by your employer, bank, or investment firm.
Less commonly, code 811 appears when you claim a refundable credit (like the Earned Income Tax Credit) and the IRS needs to verify your income or filing status before they can process it. This verification is routine and does not mean you did anything wrong.
The notice you receive will specify which line item or form triggered the code. Read that section carefully—it tells you whether the IRS is fixing it themselves or whether they need you to respond.
Refund timing if the IRS fixes it themselves
If the notice says the IRS corrected a math error or found a missing form in their own records, they will process the corrected return without asking you to do anything. In this case, expect your refund within two to four weeks from the date on the notice.
The IRS processes these corrections in batches, so the exact timing varies. Some refunds arrive in ten business days; others take the full four weeks. You can check the status using the IRS Where's My Refund tool at irs.gov. Enter your Social Security number, filing status, and the refund amount shown on your original return.
Do not file an amended return (Form 1040-X) if the IRS has already issued a code 811 notice. Sending an amended return while they are reviewing the original can delay things further.
What to do if the IRS is asking you to respond
If the notice asks you to send documents, sign a form, or provide information, you will see language like "we need you to" or "please send us." The notice will include a important date—usually 30 days from the date on the notice.
Gather what they are asking for and send it by mail to the address on the notice. Do not email it or call to ask if you can submit it another way. The IRS processes paper mail through a specific queue for code 811 cases, and deviating from that slows things down.
Include a copy of the notice itself with your response so the IRS can match your documents to your case. Once they receive your response, they will review it and issue a new notice within four to eight weeks. If everything is in order, your refund will be processed at that time.
If you need to file an amended return
Sometimes the code 811 notice reveals that you made an actual error on your return—you reported the wrong income, claimed a deduction you should not have, or missed a form entirely. In this case, you may need to file Form 1040-X (Amended U.S. Individual Income Tax Return) rather than straightforward responding to the notice.
File the amended return only if the notice specifically says to do so, or if you realize the error is something the IRS cannot fix from their end. Mail the amended return to the same address listed on the code 811 notice. Processing an amended return takes eight to twelve weeks from the date the IRS receives it.
If you file an amended return while the original is still under code 811 review, the IRS will likely process both together, which can extend the timeline. Call the IRS at 800-829-1040 only if you are unsure whether you need to file an amended return—do not call to ask about refund timing.
Using Where's My Refund to track your status
The IRS Where's My Refund tool is the only reliable way to check on a code 811 case. Go to irs.gov, select "Where's My Refund," and enter your Social Security number, filing status, and the refund amount from your original return.
The tool will show you one of three statuses: "Return Received," "Return Under Review," or "Refund Approved." If it says "Return Under Review," your case is still in the code 811 queue. The tool does not show the specific reason for the delay, but it will update when the IRS has made a decision.
Check the tool no more than once a week. Checking it multiple times a day will not speed up the process and may trigger a temporary lockout on your account. If the tool shows no information after 24 hours of filing, wait five business days before checking again.
What happens if you miss the important date on the notice
If the notice asks you to respond and you do not meet the important date, the IRS will make a information based on the information they have. This may result in a reduced refund, no refund, or a bill if the IRS determines you owe money instead.
If you miss the important date but realize it later, you can still send the requested documents. Include a letter explaining why you are responding late. The IRS will consider late responses, though there is no may provide they will change their decision. Send it to the address on the notice as soon as possible.
If you receive a notice of deficiency (a bill for taxes owed) after missing a code 811 important date, you have 90 days from the date on that notice to file a petition with the U.S. Tax Court. Do not ignore a deficiency notice.
Frequently Asked Questions
Can I call the IRS to ask them to hurry up with code 811?
No. The IRS does not prioritize code 811 cases based on phone calls. Calling will not change the timeline. If you have a genuine question about what the notice is asking for, you can call 800-829-1040, but expect a wait of 30 minutes to two hours.
Does code 811 mean I made a mistake on my taxes?
Not necessarily. Code 811 can appear for math errors the IRS caught, missing forms, or mismatches between what you reported and what employers or banks reported. Many code 811 cases result in the refund being issued as originally filed. It is a review, not an accusation.
What if I filed my return electronically and got code 811—should I file a paper return instead?
No. Filing a paper return will not help and will create a duplicate filing that the IRS has to sort out. Respond to the code 811 notice as instructed, and the IRS will process your original electronic return.
How do I know if code 811 means I owe money instead of getting a refund?
The notice will tell you. If the IRS determines you owe money, the notice will say so and explain why. If you disagree, you have the right to respond in writing. The notice will include instructions for doing so.
Can I use my refund before code 811 is resolved?
No. The IRS will not release your refund until the code 811 review is complete. You cannot borrow against it or access it early. Once the review is finished and the IRS approves the refund, it will be deposited or mailed according to your original return instructions.